While confocal microscopy uses a pinhole to reject out-of-focus light to generate the optical section, a multi-photon (or 2-photon) microscope uses a pulsed infrared laser to stimulate fluorescence ...

The result is an optical section that is slightly thicker than a typical confocal section, but can be imaged at a much faster rate. Perhaps most importantly, the sample holder can be translated in 4 ...